WELLINGTON -- Exports to all of New Zealand's top five trading partners, except China, fell last month, leading to a lower than expected trade surplus, the government statistics agency said Thursday.

The value of exported goods fell by NZ$347 million ($271.58 million), or 7.8 percent year on year, to NZ$4.1 billion in May, according to Statistics New Zealand said.

While exports to four of the country's top five export partners, Australia, the United States, Japan and the Republic of Korea, were down a total NZ$353 million, exports to China, New Zealand's second largest trading partner, were up by NZ$89 million.

"Lower goods exports to most destinations contributed to the overall fall in export values," industry and labor statistics manager Louise Holmes-Oliver said in a statement.

"Australia and United States led this fall, which was partly offset by the increase to China."

Crude oil led the fall in exports to Australia, beef led the fall in exports to the United States, while the rise in exports to China was led by pine logs.

The value of imported goods fell NZ$163 million, or 3.9 percent, to NZ$4 billion, led by falling imports of petrol and aviation fuel and mechanical machinery and equipment.

New Zealand had a trade surplus of NZ$71 million, or 1.7 percent of exports, in May, compared with an average of 11 percent over the five previous May months.

For the year ended May, the country had an annual trade deficit of NZ$869 million, or 1.9 percent of exports.